The Doctor: Logic, my dear Zoe, merely enables one to be wrong with authority.
The Doctor: Fear makes companions of all of us.
The Doctor: One day, I shall come back. Yes, I shall come back. Until then, there must be no regrets, no tears, no anxieties. Just go forward in all your beliefs, and prove to me I am not mistaken in mine.
The Doctor: That is the dematerialising control, and that over yonder is the horizontal hold; up there is the scanner, those are the doors, and that is a chair with a panda on it. Sheer poetry, dear boy. Now please stop bothering me.
The Doctor: We are not of this race. We are not of this earth. Susan and I are wanderers in the fourth dimension of space and time, cut off from our own people by distances beyond the reach of your most advanced science.
The Doctor: I learned not to meddle in other people's affairs years ago.
The Doctor: Now, now, now, don't be absurd. There's not an ounce of curiosity in me, my dear boy.
[turns to Maitland]
The Doctor: Now tell me, why are you in danger?
The Doctor: Shall we go out and have a look?
Victoria: Now, is it safe?
The Doctor: Oh, I shouldn't think so for a moment.
The Doctor: And now they've all gone...None of them could understand, not even my little Susan, or Vicki. And as for Barbara, and Chatterton...Chesterton...they were all too impatient to get back to their own time. Perhaps, I should go home, back to my own planet. But I can't...
Jamie: Have you thought up some clever plan, Doctor?
The Doctor: Yes Jamie, I believe I have.
Jamie: What are you going to do?
The Doctor: Bung a rock at it.
The Doctor: The power cable generated an electrical field and confused their tiny metal minds. You might almost say they've had a complete metal breakdown.
The Doctor: I'm so sorry, Jamie.
The Doctor: Well, now I know you're mad. I just wanted to make sure.
The Doctor: People spend all their time making nice things, and then other people come along and break them.
The Doctor: There's no point in being grown up if you can't be childish sometimes.
The Doctor: An unintelligent enemy is far less dangerous than an intelligent one, Jamie. Just act stupid. Do you think you can manage that?
The Doctor: Your leader will be angry if you kill me...I'm a genius!
Benton: What do we do now?
The Doctor: Keep it confused. Feed it with useless information. I wonder if I have a television set handy?
The Doctor: Well, Sergeant? Aren't you going to say that it's bigger on the inside than on the outside? Everybody else does.
Benton: Well, it's pretty obvious, isn't it?
The Doctor: I had to face my fear. That was more important than just going on living.
The Brigadier: Naturally enough, the only country that could be trusted with such a role was Great Britain.
The Doctor: Naturally. I mean, the rest were all foreigners.
The Doctor: As we learn about each other, so we learn about ourselves.
Russell: Who are you?
The Doctor: I've already told you. I am known as the Doctor. I'm also a Time Lord from the planet Gallifrey in the constellation of Kasterborous.
Russell: You're bonkers.
The Doctor: That's debatable.
The Doctor: Deactivating a generator loop without the correct key is like repairing a watch with a hammer and chisel. One false move and you'll never know the time again.
The Doctor: Never cared much for the word "impregnable." Sounds a bit too much like ‘unsinkable.’
Harry: What's wrong with ‘unsinkable’?
The Doctor: Nothing. As the iceberg said to the Titanic.
The Doctor: Gloop, gloop, gloop, gloop, gloop, gloop, gloop.
The Doctor: Once upon a time there were three sisters, and they lived in the bottom of a treacle well. Their names were Olga, Marsha and Irene... Are you listening, Tillie? I feel disorientated.
Sarah: This is the disorientation centre.
The Doctor: That makes sense.
The Doctor: You can't rule the world in hiding. You've got to come out on the balcony sometimes and wave a tentacle.
Lord Palmderale: Are you in charge here?
The Doctor: No, but I'm full of ideas.
Adric: Will Romana be all right?
The Doctor: All right? She'll be superb.
The Doctor: Still, while there's life, there's six of one, half dozen of the other.
Master: Woolly thinking, Doctor.
The Doctor: Yes, but very comforting when worn next to the skin.
The Doctor: Crush the lesser races. Conquer the galaxy. Incredible power, unlimited rice pudding, et cetera, et cetera.
The Doctor: Maybe I am getting too young for this sort of thing.
The Doctor: What's the use of a good quotation if you can't change it?